We will continue screening our clone bank for putative beta-glucuronidase sequences using the techniques already developed. In addition we are making plans for improved methods of colony hybridization and the preparation of a second clone bank if the first bank does not include beta-glucuronidase. If construction of a second bank becomes necessary we will utilize a series of physical and hybridization steps to enrich even further for beta-glucuronidase sequences. When the beta-glucuronidase sequence is isolated, we plan to begin genomic mapping to compare genetic variants, assay of absolute beta-glucuronidase mRNA concentrations, and efforts to measure rates of transcription.